Method of and apparatus for washing labeled bottles and separating labels from the wash liquid



Sept. 4, 1956 METHOD OF AND APPARA Filed NOV. 9, 1953 o SCHROEDER 2 761,799

TUS FOR WASHING LABELED BOTTLES AND SEPARATING LABELS FROM THE WASH LIQUID 4 Sheets-Sheet 1 FIG. I

Sept. 4, 1956 o. SCHROEDER 2,761,799

METHOD OF AND APPARATUS FOR WASHING LABEILED BOTTLES AND SEPARATING LABELS FROM THE WASH LIQUID Filed NOV. 9, 1953 4 Sheets-Sheet 2 FIG.3

Sept. 4, 1956 o. SCHROEDER 2,761,799

METHOD OF AND APPARATUS FOR WASHING LABELED BOTTLES AND SEPARATI-NG LABELS FROM THE WASH LIQUID 4 Sheets-Sheet 3 Filed Nov. 9, 1953 p 1906 o. SCHROEDER 2,761,799

METHOD OF AND APPARATUS FOR WASHING LABELED BOTTLES AND SEPARATING LABELS FRO-J1 THE WASH LIQUID Filed NOV. 9, 1953 4 Sheets-Sheet 4 FIG. 5

Ratented Sept. 4, 1956 mirror) or AND APPARATUS FOR WASHING LABELED BomES AND LABEL FROM WASH LIQ I Otto Schroeder, Napa, Calif, Application November 9,1953, No. 391,96

1.1 Zla m (L L The invention relates to the art .of separating labels and other fibrous or laminar material firom liquid, for example, from detergent solution in a bottle washing operation; it relates also .to an improved apparatus for separating the labels from iiquid and for shredding the separated labels to facilitate disposal thereof, e. g., to a sewer. The invention further relates to an improved method and apparatus for washing hottlcs that bear labels wherein the labels are removed with a detergent solution and become suspended in said solution or otherwise remain in contact therewith.

For convenience, labels will be referred to in this specification; however, it will :he :understood that similar materials may be separated from liquid according to :the invention.

In the art of washing bottles bearing labels it is common practice to pass the bottles by means of a conveyor through one or more tanks containing detergent solution. The labels become detached and either float, sink, or are suspended in the detergent for an extended time uSuaHy a matter of several days or weeks..;until the detergent is drained OE and replaced. Removal of labels between detergent changes, when practiced, is ineffective to separate the bulk of the labels from the tank and is inconvenient; since it is necessary to stop the conveyor for m n al removal of labels, i can be Pei-f rm d on y Occasionally. Many labels contain substanc s, such as pigments or coatings, that react with the detergent or are otherwise deleterious to it upon prolonged contact of the labels with the solution; it is believed that such substances become dissolved or suspended in the detergent. It was found that the useful life of detergent solutions used in h nv nti n l W sh n Proces es with u h l bels i only about one-fifth to one-half {of the life when used with other labels.

The p s l f labels r moved from the ash tanl h s a Presented Pr blem intact labels can ot be af ly f to s ry e e s and the hand ing of mas es of moist labels has been troublesome. Such labels are usually removed from the wash tanks ,nranually, requiring the services of workmen and being time-oonstuning.

It is an j c of the in ention t p ovide an imp method and apparatus for washing labelled bottles with a detergent solution wherein the labels are separated from the solution continually during the washing operation, a c in us y o in ermit ently. Ancillary thereto, it i an ic to p olong the usctul the of. de ergent solution used with labels containing ingredients deleterious to the solution by materially reducing the time that such labels r m in in c n a wi h he solu i n- Another ancillary Object is to f c ate the handling of the labels and their removal from the wash tank.

It is a further object to provide an improved apparatus for separating labels and the like from a liquid burdened therewith, such as a detergent solution. Ancillary thereto, it is an object to provide a device impressing moisture from the labels and for shredding 111 labels in a continuous operation so that the labels are comminuted and con- 2 ditioned for disposal into a sanitary sewer, stream or furnace.

Further objects will become apparent from the following description.

In summary, bottles hearing labels adhesively attached th ar co tacted in a Washing zone, e. g., a tank, with a detergent solution by spraying and/or immersion in a bath of the detergent to remove the labels and form a suspension or slurry of labels in the solution, the solution burdened with labels is Withdrawn from the washing zone while the washing operation is continued, the labels are separated promptly from :the Withdrawn solution, .and the clear solution is returned to the washingzone for furthere spraying and/ or to replenish the bath. The separator preferably includes a casing containing an annular, perforate filter wall having a frusto-conical section within which is a bladed conveyor screw, and the slurry of liquid and labels is fed into the space the larger end of the filter wall, so that the clear liquid flows as a filtrate through the filter wall and the labels are compressed by the screw and the converging filter Wall into a firm magma of reduced moisture content. The separator advantageously includes a shredder, such as one having a plurality of saw discs fixed obliquely to a shaft that rotates on an axis transverse to the path of the magma discharged from the smaller end of the filter -w a l.

The invention will be further described with reference to the accompanying drawings forming a part of this specification and showing two preferred embodiments by Way of illustration, wherein:

Figure l is an elevation view of a battery of bottle washing tanks, parts being shown section;

Figure 2 is a transverse section, taken on line 2-2 of Figure :1;

Figure 3 is a diagrammatic plan vievvof the installation, showing the piping;

Figure 4 is a sectional view .Of the separator, taken on a vertical longitudinal plane;

Figure 5 is an inclined top View of the separator, looking in the direction of the arrow .5 Figure 4;

(figure 6 is a section taken on line 6.6 of Figure 4; an

Figure 7 is a fragmentary plan view similar to Figure 3 showing a modification.

Referring to the drawings in detail, :the invention may be applled to a washing plant including one or more, for example, five, bottle waslringtanks 10*14, defined by end walls 15, 15a, side walls L6, 16:: transverse partitions 17, a fl r 1 and a root 19.. The tanks have a suitable conveyor of any type, such .as one including a pair of endless chains 2%) situated respectively near the d l S id hains supporting Suitable transverse sup- Por m ns 2. 1 for s uring a plurality of bottles 21 in transverse rows, ,e. g., with twenty-four bottles in each row. The conveyor moves over guide rollers 22 and is driven by a motor and sprocket, not shown. The conveyor system, being well known per se, is indicated only diagrammatically. The arrows 23 and 24 show the directions of travel of the loaded and empty parts, respectively. The end walls have openings 25 and 26 through which bottles bearing labels are charged to the conveyor and washed bottles are discharged, respectively. The tanks contain detergent solution to a suitable level beneath the openings 25 and 26. Each tank except the last in the series has a sprayer device, such as a transverse pipe 27 with a series of orifices along the length thereof directed to direct a spray 28 against the ascends P 29 f he c nveyo this part being almost vertical, e. g., inclinedwith the openitops of the bottles lowermost. The bottles are immersed in and moved through a bath of detergent solution in each tank and the spray 28 is directed against the bottles as they emerge from the bath to rinse off adhering labels and other matter.

Each tank has a draw-off pipe 30 connected near the tank bottom and communicating through a shut-off valve 31 with a slurry pipe32 or 32a. These valves are advantageously of the type providing a large, unobstructed passage to avoid clogging. The slurry pipes discharge into a separator 33 which may be of the type described in detail hereinafter, wherein the labels are separated from the detergent solution and discharged at 34 to a hopper 35; this may be an intake to, a sanitary sewer. The clear detergent solution is discharged through a pipe 36 to a pump 37, which may be a large, low pressure centrifugal pump driven by a motor 38. The pump discharge is connected to a main return pipe or manifold 39 which communicates with the several tanks through individual shut-off valves'40 and branch pipes 41. A branch pipe 42 receives a small part of the flow from the pipe 39 and is connected to a pump 43, which is advantageously a small, high pressure'centiifugal pump. The discharge of the pump 43 is connectedto a manifold pipe 44 which communicates through individual flow control valves 45 with the several spray pipes 27 for the constant flow of detergent liquid in regulated amounts.

, A discharge outlet 46, controlled by a valve 47, may be provided in the pipe 39 for connection to'a sewer. Similarly, a charge pipe 48, controlled by a valve49, may be connected to' the pipe 36.

Referring to Figures 4-6, the seperator comprises a base supporting an inclined lower transverse end plate 51 to which is fixed an annular wall 52 carrying an upper transverse plate 53 welded thereto and extending beyond the Wall 52 to serve as a bolting flange. An annular wall .54 carrying transverse lower-and upper plates 55 and 56 at the ends thereof is bolted to the plate 53. The Walls 52 and 54 constitute the casing,

the axis of which is inclined. The filter wall, which also has the axis thereof inclined, is situated within the casing and includes a short, annular, cylindrical section 57 and a long, frusto-conical section 58. The former sec tion may be welded to the plates 51 and 53; the latter has a peripheral flange 59 at the large end thereof which is clamped between the plates 53 and 55 while the small end thereof fits snugly within a support sleeve 64 that is bolted to the plate 56. The end of section 58 abuts a shoulder 61 in the support sleeve. Both filter sections have multiplicities of holes 62 distributed peripherally and along their lengths, The wall 52 has a horizontal liquid discharge wall 63 that is open at both ends provided thereat with bolting flanges 64, 64a; in the embodiment shown, the former is connected to the discharge pipe 36 and the latter is closed by a blank plate 65. The wall 52 further has a pair of openings through which tubes 67, 67a extend in sealed relation; these carry bolting flanges 66, 66a, respectively, at the outer ends and communicate at their inner ends with the interior of the filter wall section 57 through large openings therein, being welded or otherwise connected to the filter Wall section. The pipes 32, 32a are connected to the flanges 66, 66a to feed the, slurry into the space within the filter wall. The plates 53 and 55 have juxtaposed openings 68 at the lowermost parts thereof for the free drainage of liquid.

The filter wall contains 'a conveyor screw 69having helicoidal blades shaped to fit closely Within the said wall and secured by set screws 79 to a stub shaft 71 that is rotatably mounted in the plate 51 by a running shaft seal 7?. and extends through the plate. The shaft is driven through a reduction gear train within a gear box 73 and a belt 74 from an electric motor 75, the gear box being bolted to a plate 76 that forms a partof the base structure and themotor being bolted to a support' plate 77 that is fixed to the plates 51 and 53.

The shredder includes a casing 78 that is bolted to the plate 56 and has a discharge opening 34 (corresponding to the opening 34 of Figs. 1-3), advantageously having a bolting flange 80 for attaching a discharge duct (not shown). The casing has side walls 81, 31a through which extends a shaft 82 that may have running seals with the walls and that isrotatably mounted in bearings 83, 83a carried by the casing. The shaft is coupled to a drive shaft 84 that is rotatably mounted in a bearing 85 and carries a pulley 86 by which it is driven through a belt 87 directly from the motor 75, whereby the shaft S2 is rotated at a speed several times that of the screw 69. A series'of saw blades or cutter discs 88 is fixed to the shaft 82,. any suitable number, such as four to twelve or more being provided. These discs are spaced along the shaft axis and inclined slightly, e. g., from 5 to 20, to the plane normal to the shaft axis. The inclination is preferably such that the greatest displacement between diametrically opposite peripheral points, measured parallel to the shaft axis, exceeds the axial distance between discstmeasured center to center). In

- other Words, each disc has a part thereof overlapping a part of an adjacent disc, as shown. The discs may have any suitable outline, e. g., circular or slightly eliptical so that their peripheries lie on a common cylinder concentrio with the shaft. The discs preferably have serrated or toothed edges, as shown, although the use of edges of other design is not excluded. The discs are situated close to the upper end of the sleeve 60, which edge is preferably curved to lie on a cylinder concentric with the shaft axis, as clearly shown in Figure 4, to permit the discs to lie close to the sleeve edge all along the edge. The sleeve 60 is to be regarded "as an imperforate extension or part of the filter wall.

The operation of the separator of Figures 4-6 is as follows: Liquid burdened with labels or the like enters the space within the filter wall section 57 through the tubes 67 and 67a. This section functions as a simple filter and the bulk of the liquid flows through the holes 62 of this section into the part of the casing defined by the wall 52. The slowly rotating screw 63 pushes the labels upwards through the converging filter wall section 58, whereby the labels are compressed and moisture is squeezed out, flowing through the holes 62 of this section into the part of the casing defined by the wall 54 and through the holes 68 to join the first filtrate. The total clear filtrate is discharged through the well 63 to the pipe 36. The labels are compressed to a firm magma which contains substantially no free liquid and which is discharged upwardly through the sleeve 69 as a compacted mass.

The cutter discs 88 touch the magma emerging from a the sleeve 60 along -arcuate lines of contact that move 7 back and forth parallelto the axis of the shaft 82; be-

cause 'of the preferred relation between the axial spacing of the discs and their inclination, these lines of contact travel farther than the axial distance between discs, whereby all parts of the magma are swept by at least one disc. As the magma is pressed against the discs it is shredded into pulp. The pulp is hurled by the discs against the casing wall 78 and then falls out through the opening 34. The operation of the entire washing installation can now be described. The label-bearing bottles 21 to be washed are charged to the conveyor 20 through the opening 25 and are carried successively through the wash tanks'1014. In each tank the bottles are immersed in a bath of detergent solution; labels become soggy The labels are sepa enemas via the pump 37 and the manifold pipe .39 to the appropriate tank .or tanks through the valves 3. A ding to one method of operation, the return of clear solution is predominantly to the tank from it was withdrawn in the form of a slurry; preferably one tank at a time is thus connected to the separator circuit for suitable periods. Since the liquid level in the tank is not materially altered by this circulation it is evident that the removal of labels proceeds without interruption of the washing operation. It may be noted that .the level of the tank bottom is practically at the level of the inlet to .the separator 33, whereby fiow will begin with but little head from the tank; the pump is also at a low level to insure priming. Since the casing of the separator is closed except for the sleeve 60 and the latter is, during operation, effectively sealed by the compressed magma therein, suction from the pump is transmitted through the tubes 67, 67a to the pipes 32, 32a.

A small portion of the clear detergent solution is pressurized by the pump 43 and forced as a spray from the pipes 27. The resulting spray 28 rinses off labels and other material adhering to the bottles and conveyor just before leaving each tank except the last, thereby reducing carryover between tanks.

it is evident that the several tanks will not normally be subjected to circulation of detergent solution for equal time periods; thus, since labels are for the most part removed in the first two tanks, circulation occurs for longer periods in these tanks than in subsequent tanks. Some circulation or at least removal of detergent is, however, necessary from subsequent tanks that receive spray solution, so as to re-establish the liquid level therein; it is evident that for reducing the liquid level in a tank the detergent is returned to a different tank.

According to another mode of operation, the detergent solution can be progressively transferred from tank to tank. 'I' hus, soiled detergent solution can be discharged from the tank through the separator, pump 37, outlet 46 and valve 47 until part .or all of the detergent in this tank is removed from the system. The valve 47 is then closed and detergent solution from the tank 11 is passed through the separator 33, pump 37 and manifold 39 and charged to the tank 10. This is repeated with each .pair of adjoining tanks in succession until the tank 14 is wholly or partly drained; fresh or make-up detergent is then supplied through the inlet 48, valve 49, pump 37 and manifold 39 to the tank 14. In this mode of operation the sprays 28 may be continued in operation; the immersion part of the washing operation is temporarily ineffective or less effective in each tank in succession, to an extent that depends upon the level to which the solution is drained. However, this mode of operation has the advantage of employing the cleanest detergent solution in the last tank, thereby applying the principle of countercurrent flow between detergent solution and bottles.

It was found that this system greatly reduces the effective time of contact between labels and detergent solution. Although not all labels are removed from the tanks, their number is greatly reduced so that deleterious ingredients of the labels have less opportunity to damage the detergent. For example, the useful life of the detergent solution may be increased two-fold to fivefold as compared with the life of detergent with the usual washing systems wherein the labels are not removed during the washing operation.

According to a variant shown in Figure 7, each drawofi pipe 30 is connected to a branch line 39a through a valve 39b and an oblique pipe 390, disposed to supply a liquid jet into the valves 31. The line 39a is supplied with clear detergent solution from the manifold 39, as shown, or at a higher pressure, e. g., from the manifold 44. In operation the appropriate valve 3% is opened when necessary to fiush out labels that may accumulate in the associated valve 31 or other parts of the system. The pipes 390 are disposed obliquely to 6 ve the j a velocity mponent toward th v l es 1 but Preferably to n ex end into e pipe 30, o as no to create any obstruction therein.

I claim as my invention:

1. Method of removing labels from bottles bearing said labels adhesively attached thereto by contact with a detergent solution, said labels containing a substance that is deleterious to said detergent solution upon prolonged contact therewith, including the steps of: maintaining a bath of said detergent solution in a washing tank; continuously immersing said bottles with labels in said bath and thereby causing the labels to be removed from the bottles and to form a slurry in said bath; continuously removing bottles from said bath and discharging said bottles from the tank; continuing the said immersion and removal of bottles over a protracted period of time; withdrawing from said bath during said protracted period a portion of the said slurry; separating the labels from said withdrawn slurry by continuous flow through a separator; returning a portion only of the detergent solution, after passage through the separator, directly to said bath at a low pressure; pressurizing another portion of said detergent solution from the separator to a higher pressure; and returning the said pressurized portion to said tank as a spray directed against the bottles after removal from the bath.

2. Apparatus for washing bottles bearing labels adhesively attached thereto by contact with a detergent solution, comprising in combination: a washing tank adapted to contain a body of said detergent solution; a conveyor for bottles including a descending part for immersing bottles in said body of detergent solution and an ascending part for removing said bottles from said body; a sprayer mounted to .direct a high velocity jet against bottles in said ascending part of the conveyor for the removing adhering labels therefrom and carrying the last-mentioned labels back into the tank; a detergentsupply conduit connected to said sprayer; and outlet for said tank in free communication therewith for the discharge of detergent solution burdened with labels; a separator for separating labels from detergent solution having an inlet connected to said tank outlet, an outlet for seperated labels, and a detergent outlet for detergent solution; a low-pressure return conduit interconnecting said detergent outlet to the washing tank for the return .of a portion of the detergent solution from said detergent outlet; a low-pressure pump connected to induce flow of detergent solution through said low-pressure feturn conduit; and a high-pressure pump having the intake thereof connected to receive another portion of the detergent solution from said detergent outlet and having the discharge thereof connected to said supply conduit of the sprayer for supplying said other portion at a higher pressure to said sprayer.

3. Apparatus for separating labels and the like from liquid including, in combination: a perforate filter wall having a frusto-conical part and being open at the smaller end thereof; conduit means for admitting liquid burdened with solids into the space within the larger end of the filter wall; a casing surrounding at least the perforated portion of said filter wall for collecting liquid; a liquid outlet for said casing; a conveyor screw having a helicoidal blade rotatably mounted within said filter Wall; a rotatable shaft extending transversely across the said smaller open end of the filter wall bearing cutter elements situated in close proximity to said open end for shredding solids discharged from said open end of said filter wall; and means for rotating said screw and shaft.

4. Apparatus according to claim 3 wherein said filter wall is disposed with said smaller end of the frusto-conical part elevated above the larger part thereof, whereby the bulk of said liquid can flow through the filter wall at the lower end thereof.

5. Apparatus according to claim 3 wherein said cutter liquities of the discs being such that adjacent discs overlap in the direction of the shaft axis, said discs having their peripheries situated in close proximity to the end of the fllter wall.

7. Apparatus according to, claim 6 wherein said filter 'wallhas a tubular imperforate portion at the same smaller open end, the said imperforate portion having the end thereof shaped to a cylinder concentric to said shaft and the said discs being situated with the peripheries thereof substantially at said cylinder.

8. Apparatus for separating labels and the like from liquid including a perforate filter wall having a frustoconical part with the smaller end thereof open; a terminal wall sealed to said filter wall'at the end thereof remote from said smaller end; conduit means for admitting liquid burdened with solids into the space within the filter wall near'said terminal wall; a casing surrounding at least the perforated portion of 'said filter wall for collecting liquid;

at liquid outlet for said casing;,a conveyor screw having a helicoidal blade situated within said filter wall; a retatable shaft extending through said terminal wall in liquid-tight relation thereto at the axis of said screw, said screw being fixed only to said shaft; means on the side of said wall opposite the screw for rotating said shaft,

thereby to rotate the said screw; a short imperforate tube aligned with an jointed to, said filter wall at'the said smaller end thereof for receiving said labels as at film magma under the pressure of said conveyor screw; a shredder shaft rotatably mounted with the axis thereof transverse to and beyond the end of said tube and substantially on the tube axis; and shredder elements on said shredder shaft for rotation therewith, said tube having the end thereof remote from the filter wall curved to conform substantially to a segment of the cylinder generated by the peripheries of said shredder elements upon rotation thereof. I

9. Apparatus according to claim 8 wherein said shredder elements are cutter discs fixed to said shredder shaft obliquely to the axis thereof and spaced along the shaft, the obliquities of said discs being such that adjacent discs overlap in the direction of the shredder shaft, axis.

10. Apparatus for separating labels and the like from liquid including a casing having upper and lower sections, the lower section including an annular wall and transverse upper and lower terminal walls of which the upper has openings, and the upper section including an annular wall secured at the near end thereof to said lower section and having a remote transverse terminal wall with an opening therein; a perforate annular filter,

wall within said casing including a lower section situated within the lower casing section and secured to said upper and lower transverse walls in register with an opening in said upper transverse wall, and an upper section .fz'usto-conical in shape with the lower, larger end thereof juxtaposed to said lower section; a support sleeve fixed to said remote terminal wall at said opening therein, the smaller end of the upper filter wall section extending into said support sleeve and having an abutment therein;

conduit means for admitting liquid burdened with solids into the space within the lower. filter wall section; a liquid outlet for said lower casing section; a conveyor screw having a helicoidal blade situated within said filter wall; 'a shaft rotatably mounted and extending through the said lower terminal wall in liquid-tight relation thereto at the axis of said screw, the said screw being fixed only to said shaft; and means beneath said lower terminal wall for rotating said shaft, thereby to rotate the said screw. 7 p

11. Apparatus according to claim 10 wherein said upper casing section has a near transverse terminal wall at the near end thereof, said wall having openings in register with openings in said upper terminal wall of the lower casing section, and the said upper section of the filter wall has a peripheral flange clamped between the said upper terminal wall and the said near transverse terminal wall.

References Cited in the file of this patent UNITED STATES PATENTS 228,041 Cowan May 25, 1880 332,718 Laiferty Dec. 22, 1885 901,969 Hoover Oct. 27, 1908' 1,381,347 Schaller June 14, 1921 1,564,187 Ahrens Dec. 8, 1925 2,050,634 Stegemann Aug. 11, 1936 2,311,391 Herold Feb. 16, 1943 2,314,048 Ladewig Mar. 16, 1943 2,529,762 Brisse Nov. 14, 1950 FOREIGN PATENTS 323,273 Germany July 19, 1920 365,378 1938 Italy Dec. 2; 

1. METHOD OF REMOVING LABELS FROM BOTTLES BEARING SAID LABELS ADHESIVELY ATTACHED THERETO BY CONTACT WITH A DETERGENT SOLUTION, SAID LABELS CONTAINING A SUBSTANCE THAT IS DELECTERIOUS TO SAID DETERGENT SOLUTION UPON PROLONGED CONTACT THEREWITH, INCLUDING THE STEPS OF: MAINTAINING A BATH OF SAID DETERGENT SOLUTION IN A WASHING TANK; CONTINUOUSLY IMMERSING SAID BOTTLES WITH LABELS IN SAID BATH AND THEREBY CAUSING THE LABELS TO BE REMOVED FROM THE BOTTLES AND TO FORM A SLURRY IN SAID BATH; CONTINUOUSLY REMOVING BOTTLES FROM SAID BATH AND DISCHARGING SAID BOTTLES FROM THE TANK; CONTINUING THE SAID IMMERSION AND REMOVAL OF BOTTLES OVER A PROTRACTED PERIOD OF TIME; WITHDRAWING FROM SAID BATH DURING SAID PROTRACTED PERIOD A PORTION OF THE SLURRY; SEPARATING THE LABELS FROM SAID WITHDRAWN SLURRY BY CONTINUOUS FLOW THROUGH A SEPARATOR; RETURNING A PORTION ONLY OF THE DETERGENT SOLUTION, AFTER PASSAGE THROUGH THE SEPARATOR, DIRECTLY TO SAID BATH AT A LOW PRESSURE ANOTHER PORTION OF SAID DETERGENT SOLUTION FROM THE SEPARATOR TO A HIGHER PRESSURE; AND RETURNING THE SAID PRESSURIZED PORTION TO SAID TANK AS A SPRAY DIRECTED AGAINST THE BOTTLES AFTER REMOVAL FROM THE BATH.
 3. APPARATUS FOR SEPARATING LABELS AND THE LIKE FROM LIQUID INCLUDING, IN COMBINATION: A PERFORATE FILTER WALL HAVING A FRUSTO-CONICAL PART AND BEING OPEN AT THE SMALLER END THEREOF; CONDUIT MEANS FOR ADMITTING LIQUID BURDENED WITH SOLIDS INTO THE SPACE WITHIN THE LARGER END OF THE FILTER WALL; A CASING SURROUNDING AT LEAST THE PERFORATED PORTION OF SAID FILTER WALL FOR COLLECTING LIQUID; A LIQUID OUTLET FOR SAID CASING; A CONVEYOR SCREW HAVING A HELICOIDAL BLADE ROTATABLY MOUNTED WITHIN SAID FILTER WALL; A ROTATABLE SHAFT EXTENDING TRANSVERSELY ACROSS THE SAID SMALLER OPEN END OF THE FILTER WALL BEARING CUTTER ELEMENTS SITUATED IN CLOSE PROXIMITY TO SAID OPEN END FOR SHREDDING SOLIDS DISCHARGED FROM SAID OPEN END OF SAID FILTER WALL; AND MEANS FOR ROTATING SAID SCREW AND SHAFT. 